i posted a few pix on my profile... but thanks for the info... i'm really scared...
This doesn't sound like an STD. You don't say whether your anus has been sexually exposed in any way, but even if so, it sounds more like an injury or a hemorrhoid, perhaps with a secondary non-STD infection. The main thing is to get professionally evaluated; see your doctor as soon as possible. Not an emergency, but try to see someone in the next day or two.